The present invention relates to a magnetic device with retaining strength to move, affix or carry ferromagnetic parts or loads provided with electronic switching of the magnetic flux to release the carried load.
The moving or carrying of ferromagnetic parts or loads is basically achieved by two means: (a) devices known as permanent load magnets, operated manually or electrically, wherein magnetic attraction is created by moving their cores with consequent change in the orientation of the magnetic flux lines; and (b) electromagnets, wherein artificial magnetic attraction is created by an electric current flowing through a coil. By causing variations in some factors, such as dimensions and current intensity, the electromagnet is capable of lifting and moving ferromagnetic objects ranging from thin blades up to articles weighing tons. Problems, however, are posed by both of the aforementioned devices. In permanent load magnets, lack of safety is an ever-present condition, due to high dispersion of the magnetic flux, and operation is sluggish, requiring external sources of energy (motor) when the weight to be carried it very high, since the magnet's power of attraction is closely related to its own size. In the case of electromagnets, if some external agent causes even an instantaneous lack of electric power, they lose their power of attraction and the ferromagnetic load being carried will drop away. Additionally, the consumption of power for maintaining the attraction is very high.